Classification
304 - Factors affecting social behavior
48
338 - Production
31
333 - Economics of land & energy
23
577 - Ecology
18
551 - Geology, hydrology & meteorology
3
370 - Education
2
621 - Applied physics
2
658 - General management
2
003 - Systems
1
170 - Ethics
1
174 - Occupational ethics
1
361 - Social problems & social welfare in general
1
363 - Other social problems & services
1
371 - Schools & their activities; special education
1
550 - Earth sciences
1
613 - Personal health & safety
1
629 - Other branches of engineering
1